Thousands of Philadelphia students walked out of their schools on Wednesday in recognition of the grim reality that any one of them could be the next target of a madman with a gun.

Students walked out for at least 17 minutes in tribute to the 17 students and teachers murdered inside Marjory Stoneman Douglas High School in Parkland, Florida. Many marched for hours more.

At Germantown Friends School (GFS), hundreds of students from middle and upper schools stood silent for 17 minutes along Coulter Street near Germantown Avenue, under a painted banner reading "#Enough."

"Every minute that passed, I was thinking of every individual kid who lost their life in this tragedy," said Asaf Lebovic, 14, a freshman at GFS who co-organized the walkout. "I'm horrified that we even had to walk out today. This is something that should have been solved already."

Students at GFS said that, while they may not be old enough to vote, they wanted to raise their voices, and show solidarity with students who survived Parkland.

Despite the horror and violence of mass shootings, some students said they felt uplifted by the support they gave one another.

"Just to see everyone filled me with hope," said Sona Wink, 14, co-organizer of GFS' walkout. "We really need that right now. It can feel so bleak after we hear about these shootings because it feels like nothing's happening. This feels like change."

At the nearby Pennsylvania School for the Deaf (PSD), many of the school's 200 students held a 17-minute moment of silence along Greene Street.

"Our students are responding with grief, sadness, fear, concern, shock that that kind of thing can happen anywhere," PSD head of school Peter Bailey said through a sign language interpreter of his students' and staff's reaction to Parkland. "I think the students primarily wanted to participate because they're experiencing a lot of that sadness and grief."

Bailey described his school as not participating with any political message in mind, save solidarity with the victims in Parkland, and said their school has security protocols in place they would follow in the event of a crisis.

But walking out in tribute to the victims of past shooting inevitably brought concerns that any American school could be next.

"It was really tough. It was an emotional experience," Bailey said. "As head of school, I have a responsibility to the students and staff here, looking out for them and making sure they're safe. Of course, I had thoughts about the kinds of things that could happen. But I want to stay primarily focused on the ways that we're in good hands and the ways that we'll be keeping our students safe."